import org.junit.Test;

import java.util.HashMap;
import java.util.Map;

/**
 * @Author: wolfengi
 * @Description: ${TODO}
 * @Date: Created in 9:24 2020/5/22
 * @Modified By:
 */
public class T01 {

    @Test
    public void t1() {
        Map<String,Integer> map = new HashMap<>();
        Integer a = map.get("a");
        System.out.println();
    }
}
